The glucosinolates-myrosinase system: From chemistry, biology to ecology

Glucosinolates, a well-defined, sulfur-rich class of plant secondary products mainly confined to various crops of the family Brassicaceae, are of prime importance in agriculture and plant biotechnology since the discovery of their role in plant defense against insect herbivory. Till date more than 120 different types of the compound have been reported. The enzyme myrosinase (thioglucosidases), which is stored in specialized plant cells, converts glucosinolates to the several toxic products (e.g., isothiocyanates, thiocyanates, and nitriles). The hydrolysis products have many different biological activities for plants, e.g., as defense compounds as well as attractants. In case of human, they may play several roles as biopesticides, flavor compounds and cancer-preventing agents. In the present article, we try to discuss broadly the biochemistry and the roles of the compounds, their break-down products in the insect-plant relationships and multitrophic interactions. Major focus has been laid on Brassicaceous crop plants, where they are most abundantly found.